Water-washing accelerating composition for silver halide color photographic light sensitive elements

ABSTRACT

A water-washing accelerator for silver halide color photographic light-sensitive elements which comprises an aqueous solution containing at least one of the following: acetic acid, propionic acid, butyric acid, itaconic acid, citraconic acid, aconitic acid, phthalic acid, and derivatives thereof. A process for accelerating the removal of chemicals remaining in a color photographic light-sensitive element comprises processing the element after fixing in the presence of one of the above members or the derivatives thereof.

United States Patent Shibaoka et al. 5] Mar. 14, 1972 [54] WATER-WASHING ACCELERATING [56] References Cited COMPOSITION FOR SILVER HALIDE UNITED STATES PATENTS COLOR PHOTOGRAPI'IIC LIGHT 2 657 139 10/ 953 B 96/56 L l ates SENSITIVE E EMENTS 2,515,121 7/1950 Harsh et al ..96/56 [72] Inventors: Haruo Shibaoka; Shunichiro Tsuchida,

both of Kanagawa, Japan Primary Examiner-Norman G. Torchin Assistant ExaminerEdward C. Kimlin [731 Asslgnw Full Kanagawa, Anomey-Sughrue, Rothwell, Mion, Zinn and Macpeak Japan 22 Filed: Oct. 2, 1968 [571 ABSTRACT [21] APPLNOJ 764,614 A waterwashing accelerator for silver halide color photo graphic light-sensitive elements whlch comprises an aqueous solution containing at least one of the following: acetic acid, [30] Foreign Application Priority Data propionic acid, butyric acid, itaconic acid, citraconic acid, aconitic acid, phthalic acid, and derivatives thereof. A process Oct. 2, 1967 Japan ..42/63360 for accelerating the removal ofchemicals remaining in acolor photographic light-sensitive element comprises processing the U-s. [5 [58] Field of Search ..96/56, 55, 60, 61, 62

3 Claims, No Drawings WATER-WASHING ACCELERATING COMPOSITION FOR SILVER I-IALIDE COLOR PHOTOGRAPHIC LIGHT SENSITIVE ELEMENTS BACKGROUND OF THE INVENTION Field of the Invention The present invention relates generally to color photography, and more particularly to a composition for accelerating water washing of silver halide color photographic light-sensitive elements.

Description of the Prior Art In the photographic processing of silver halide color photographic light-sensitive elements, after fixing the developed color photographic elements in a fixing composition containing a thiosulfate, unnecessary chemicals remaining in the photographic elements must be removed by water washing as in the case of processing silver halide black and white photographic light-sensitive elements. If the chemicals used in photographic processings remain in color photographic lightsensitive elements thus processed, the color images obtained tend to cause discoloring or fading, and in particular, since thiosulfates contained in the fixing solution are chemically unstable, if such a thiosulfate remains in color photographic light-sensitive elements, it tends to be decomposed to generate sulfur compounds, which have a harmful affect on the color images. Accordingly, such chemicals must be removed from the processed color photographic elements as completely as possible.

A single or double weight black and white photographic paper must usually be washed in flowing water for about 1-2 hours to preserve the images obtained for a long period of time. In color photographic papers, silver images are not present, as they are removed by bleaching. It could be assumed that the influence of the remaining thiosulfate is less than in the case of the black and white photographic paper, but it is still necessary in treating color photographic papers to wash them for a considerable period of time.

In order to shorten the water-washing period, a bath of various inorganic salts, in particular, an aqueous solution of sodium sulfite, is usually employed in the photographic processing of black and white photographic light-sensitive elements. By using such a conventional process, the washing period can be shortened to one-third to one-fourth of the time required when such salts are not used.

However, when a color photographic light-sensitive element is processed in a water-washing accelerating solution containing a sulfite, carbonate, or phosphate, or mixtures thereof, fading occurs in one or all of the cyan, magenta and yellow layers and excessive recoloring occurs in some cases thereby causing loss of the color balance of the three layers, which makes photographic processing in this manner unacceptable. In particular, when sodium sulfite is employed in the waterwashing accelerating solution the fading of cyan layer is remarkable.

SUMMARY OF THE INVENTION An excellent water-washing accelerating composition for silver halide color photographic light-sensitive elements which comprises an aqueous solution containing at least one member selected from the group consisting of acetic acid, propionic acid, butyric acid, itaconic acid, citraconic acid, aconitic acid, phthalic acid, and derivatives thereof, has been discovered.

This composition may also be utilized in a novel process for accelerating the removal of chemicals remaining in a color photographic light-sensitive element which has been subjected to photographic processing. The novel process basically comprises subjecting the color photographic light-sensitive element to processing in the presence of a member selected from the group consisting of acetic acid, propionic acid, butyric acid, itaconic acid, citraconic acid, aconitic acid, phthalic acid, and derivatives thereof, after the photographic light-sensitive element has been fixed.

The inventors have investigated water-washing accelerators and have found that certain carboxylic acids and derivatives thereof are effective for accelerating the water-washing of the thiosulfate in photographic light-sensitive elements.

Thus, an object of this invention is to provide a water-washing accelerator composition for color photographic light-sensitive elements which does not have an undesirable influence on the color images.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Many carboxylic acids and derivatives thereof have a waterwashing accelerating effect, but they generally have an undesirable influence on the color images of the color photographic light-sensitive elements thus processed. However, it has been found that certain compounds have no such undesirable influence.

The water-soluble carboxylic acids and the derivatives thereof employed in the present invention as the improved water-washing accelerator are acetic acid, propionic acid, butyric acid and the alkali metal salts of the acids; itaconic acid, aconitic acid, citraconic acid, mesaconic acid, and the alkali metal salt anhydrides of these acids or the esters of the acids; and phthalic acid, phthalic anhydride and alkali metal salts of phthalic acid. These compounds can be used as a water-washing accelerator for shortening the washing period of time to one-fourth to one-sixth of the washing period of time by conventional water washing, and have no undesirable influence on the color images.

These compounds may be used alone or as mixtures of two or more such compounds. The water-washing accelerator may, of course, be added to a washing solution or water-washing accelerating bath after fixing and it may be added to other baths between fixing processing and water-washing, such as, a hardening bath or a stabilizing bath.

The effective amount of the water-washing accelerator is more than 0.01 mole/liter, but best results are obtained in the range of ODS-0.5 mole/liter.

The pH of the solution for the water-washing acceleration of color photographic elements is preferably 4.59. The pH of the water-washing accelerator solution may be adjusted by using sodium hydroxide, acetic acid or sulfuric acid without giving any undesirable influence on color images. Furthermore, the water-washing accelerator solution of this invention may contain other additives such as precipitation preventing agents, buffers, ultraviolet absorbers, fluorescent whitening agents, and the like, in amounts which give no undesirable influence on the color images. These are commonly used materials by those skilled in the art.

The invention will be explained in detail by the following example, although the invention is not to be limited to the example.

EXAMPLE After exposure, a color photographic printing paper was subjected to conventional color photographic processings, and after final fixing, was immersed in an aqueous solution containing the additive shown in the following table for two minutes, thereafter washed with water for 5 minutes at a temperature lower than 17 C., stabilized and then dried.

In the table, Experiment 1 stands for a control using only water; experiments 2 to 10 stand for the examples of the compounds suitable for the purposes of the present invention, and experiments ll to 14 stand for the examples of unsuitable compounds. In these experiments, an aqueous solution of 0.2 mole/liter of the additive was used, and the temperature and the pH of the solution were 20 C. and 7, respectively.

After final water washing, the amount of sodium thiosulfate remaining in the color photographic printing paper was measured, and the photographic densities of a red-sensitive layer (R), a green-sensitive layer (G) and a blue-sensitive layer (gray images in the high density portion and the low density portion) were determined, the results of which are shown in the following table.

Amount of Difierenee in photographic density from control remaining sodium High density portion Lower density portion thiosullate Experiment Number Compound used as accelerator (0.2 molil). (pg/cm?) R G B R G B (l) Water (control). 13 0 0 (l 0 0 (2).. Acetic acid A 0 0.02 0. 01 0 0 0 (3).. Propionic acid. 0 +0. 01 0. 01 0 0 (I U (4).. n Itaconic acid. 6 +0.01 0 0 0 0 0 (5). Dimethyl itaeonate 6 0. 01 0 0 0 (l 0 (6) Citraconic acid 6 0.0Z 0. 01 0 0 0 0 (7) Dimethyl citracouate 6. 5 -0.02 +0. 01 0 (l 0 0 (8).. Acunitic acid 5 0.02 0 0 0 0 0 t9)" Phthalie anhydride 4. 5 0.02 +0. 01 0 0 0 l) (10). Potassium hydrogenphthalate 6 0. 01 +0.01 0 0 0 0 (I1)- Sodium sulfite 6 -O. 07 CLM +0. 02 0. 04 0. 01 +0. 01 (I3)- Sodium citrate- 6 +0.01 0. 05 0 +0. 03 0 +0. Ol (13) Diglycolie acid 6 0.04 0.03 +0.01 -0.02 0. 01 (14) Tartric acid 5. 5 0. 01 0. 05 0 0 0 0 In general, if the variation of the photographic density of red, green or blue in color photographic printing paper is higher than $0.03, the variation can be visually observed. In particular, even if a portion of these three layers is greatly varied in photographic density, the color balance of the color image is lost, which makes the color photograph thus obtained unacceptable. As shown in the above table, when the compounds of experiments 2 to 10 are employed, the photographic density scarcely varied, and was almost identical to the control.

In addition, the amount of sodium thiosulfate was less than one-half of that of the control. In order to reduce the amount of the remaining sodium thiosulfate in the color photographic paper to less than wig/cm, the photographic paper must be washed in flowing water for more than 30 minutes. Accordingly, it is clear that the water-washing period is reduced to about one-fifth that of the control by employing the compounds of this invention, without giving any substantial undesirable influence on the color images.

The invention was explained in the above example for the case of processing color photographic papers, but it will be understood that the water-washing accelerator of this invention may also be applied to color photographic light-sensitive films.

What is claimed is:

l. A process for accelerating the water washing of a color photographic light-sensitive element subjected to photographic processings which comprises processing said color photographic light-sensitive element after fixing and before washing in an aqueous solution containing a member selected from the group consisting of itaconic acid, aconitic acid, phthalic acid, phthalic anhydride, and an alkali metal salt of phthalic acid.

2. The process as claimed in claim 5 wherein said solution is a hardening bath.

3. The process as claimed in claim 5 wherein said solution is a stabilization bath. 

2. The process as claimed in claim 5 wherein said solution is a hardening bath.
 3. The process as claimed in claim 5 wherein said solution is a stabilization bath. 